1. Industrial Field
The present invention relates to an oral composition which comprises triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether) and more particularly, to an oral composition wherein the lowering in activity of triclosan by surface active agents can be prevented and the germicidal activity of triclosan is shown to a satisfactory extent.
2. Prior Art
It is known that oral compositions such as dentifrice which comprise triclosan as an effective ingredient can inhibit the formation of dental plaque because of the intense germicidal action of triclosan. In fact, there has been proposed incorporation, in oral compositions comprising triclosan, of zinc salts (Japanese Laid-open Patent Application Nos. 60-239409 and 3-127719, and Japanese Patent Publication No. 64-10489), copper compounds (Japanese Laid-open Patent Application No. 62-89614), polyethylene glycol (Japanese Laid-open Patent Application No. 62-126116), and the like.
However, when triclosan and a surface active agent such as alkyl sulfates ordinarily used as a foaming agent are used in combination, the germicidal activity is considerably lowered, with the problem that the effect of triclosan is not shown satisfactorily. In order to solve this problem, the present applicant already proposed the formulation of phenolic compounds (Japanese Laid-open Patent Application No. 2-11511) or water-soluble calcium salts (Japanese Laid-open Patent Application No. 3-5416) in an oral composition which comprises triclosan and a surface active agent. More effective measures for the dissolution are desirable.
It is essential to add a surface active agent to an oral composition such as dentifrice in order to make foams on use and to improve the feel in use. In particular, alkyl sulfates which are anionic surface active agents are most widely employed for this purpose. However, it presents a serious problem that triclosan which is added to oral compositions is impeded in activity by means of surface active agents. There is a demand of inhibiting the lowering in the activity of triclosan by surface active agents.